{
  "type": "json_schema",
  "json_schema": {
    "name": "comparison_response",
    "strict": true,
    "schema": {
      "type": "object",
      "properties": {
        "item1": {
          "type": "string",
          "description": "First item being compared"
        },
        "item2": {
          "type": "string",
          "description": "Second item being compared"
        },
        "winner": {
          "type": "string",
          "enum": ["item1", "item2", "tie"],
          "description": "Which item is better or if they're equal"
        },
        "reasoning": {
          "type": "string",
          "description": "Explanation of the comparison and decision"
        }
      },
      "required": ["item1", "item2", "winner", "reasoning"],
      "additionalProperties": false
    }
  }
}